Hello Jack I'm interested to see what other listers may have to say about your clouding questions. I don't think I've seen a definitive answer to it yet.
>I am wondering if this is all very usual, or if there is a quicker >way to get the settle/wash done. Mark, if you read this, what was the outcome of your bubble-drying work? Did you get to the bottom of it? Check these out Jack: http://nnytech.net/~archive2/index.php?view=19230&list=BIOFUEL http://nnytech.net/~archive2/index.php?view=20311&list=BIOFUEL Just a suggestion - you could try washing the oil first. Try it with a couple of test batches, two ways, with cold water and with hot. Add about 50% water and bubblewash for half an hour, let settle, drain and dry, process. With hot water, heat the oil to about 60 deg C, pour about 50% much hotter water on top, 85-90 deg C, check the combined temperature and maintain at that temp, bubblewash for half an hour, cut heat, settle, drain, dry and process. I've done this a couple of times with oil that titrated well but obviously had various impurities in it and it worked well. Maybe it'll work for you, maybe not. Please let us know the result. Best wishes Keith >Hi all - I am wondering if you all could help me clarify a few >production questions. Let me describe a bit the conditions I am >working with. >First, my oil is very good quality wvo from a cruise ship. They use >it 1-2 days and then give it to us. My titrations routinely give me >a value of around .3 - .5 extra grams of lye/liter ( I use a >biurette for titration, so small quantities to 1/10th ml are fairly >easy to determine). My batch sizes are presently about 40-50 >gallons and I am using 23% methanol to ensure that the reaction goes >far enough. I am preheating my oil to 120 F and filtering, though >only coursely (through 4-ply steel screen), before pumping into >reaction tank. I pump the hot oil from about 6" off bottom of drum >to avoid getting any residual water. Once in the reaction tank, I >am no longer able to maintain heat, so the temp falls off from there >during the reaction. The methoxide I mix with both a high rpm mixer >and a circulating pump for about 20-30 minutes. I mix the whole >batch with the same mixer for 3-4 hours - it is quite vigorous. I >let it sit after mixing for about 24 hours, but I do not stir the >glycerol back in. >Here is what I am seeing: >1 -for a 40 gallon batch of veggie oil, I am getting only about 5 >gallons of glycerol seperating out on bottom. Does this seem like a >normal amount? I used 9.2 gallons methanol and 3.8g/liter NaOH - >totaling 575g. >2 - The biodiesel on top is also still cloudy. This is puzzling to >me, but I am still not quite sure if it is normal. I have other >tanks that I let it settle in for about a week and some more fatty >substances fall out (more glycerol? tallow esters?). But it is >still not totally clear. When I go to wash, it is usually a painful >process - takes forever. First wash comes out white, second less so >and third pretty darn clear, but the biodiesel is still not totally >clear (usual?). I am adding 10 ml/L of white vinegar to the wash, >but I am concerned to use more to avoid converting back to FFA's. >If I heat to 90-100 degrees F, it seems to clear and sometimes >remains clear, sometimes not. If it does, I filter and use it. If >not I wait longer, and eventually........it clears. > >I am wondering if this is all very usual, or if there is a quicker >way to get the settle/wash done. I am trying right now to process >all of the 100 gallons a week in a 50 gallon processor, so I am >doing two batches and my settle/wash tank space is tight. Would >stirring glycerol back in help? More/less Methanol? > >I have searched the archives and found a ton of useful info, but I >was hoping someone might have a minute to comment on some of the >particulars of my situation. Thanks in advance for any assistance. > >Best, >Jack > >Jack Kenworthy >Sustainable Systems Director >The Cape Eleuthera Island School >242-359-7625 ph. 954-252-2224 fax >www.islandschool.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
